Support COSE receipts in CCF

[maxtropets]

### Tasks
- [x] get_cose_sign1_signature() API in historical queries
- [x] get_cbor_merkle_proof() API in historical queries

[achamayou]

API names and shapes may vary :)

[maxtropets]

Do we need a specific API call to get sign1_signature? Isn't it just enough to populate TxReceiptImpl with the value?

[achamayou]

@maxtropets we need a specific API to construct the proof, and add it to a uhdr param in the signature. That's what users will want to get in the end.

[maxtropets]

Just to clarify the final structure of the CBOR in question

[] - array
{} - map
() - sequence

COSE [
  phdr {
    ...
  }
  uhdr {
    leaf: int -> arr [
        wsd: bstr
        ce: tstr
        cd: bstr
    ]
    path: int -> arr [
        [left: bool, root: bstr]
        [left: bool, root: bstr]
        ...
        [left: bool, root: bstr]
    ]
  }
  payload (null)
  sig (
    bytes
  )
]

[maxtropets]

Discussed with @achamayou, due to the RFC still being developed at the moment we will provide two separate things to the caller.

• leaf and path encoded as a bstr .cbor map
• cose_sign1 of a merkle root

The caller's ought to enclose the proof into the cose_sign1 unprotected headers section. This will allow to avoid issuing new CCF releases for each RFC change until it's finalised. Afterwards we might discuss providing an API for a ready-to-go COSE receipt compilation.